An exotic range of crawling predators was stolen from a pet shop in Ossett.
Thieves made off with a pair of adult Guyana pinktoe tarantulas, which can grow up to six inches in length, from Reptilia, on Towngate.
They also took a Chilean scorpion and a range of baby tarantulas and their containers when staff weren’t looking.
The babies, which ranged from 1cm to 7cm in length, included pairs of greenbottle blue, Colombian giant brown, Costa Rican tiger rump, salmon pink birdeater and Panama blonde spiders.
Although tarantulas contain venom, most pose no threat to humans.
Reptilia owner Deborah Tate said there was no need for people to worry about the ones that had been stolen.
She added: “We’re just worried that whoever has taken them won’t know how to look after them. They’ve all got to be kept at a certain humidity.
“We believe they will have been stolen for resale. They are not rare species, but they are quite expensive and can be difficult to get hold of.
“We are well-known in the reptile-keeping community and have probably got the biggest tarantula sales in Yorkshire. It’s a close community and there aren’t many of these species around, so they would be quite easy to identify.”
Ms Tate said security had been improved in the shop.
She added: “The spider section used to be unlocked so that people could have a good look, but we’ve had to put a new pane of glass in now.
“It’s another case of a minority spoiling it for the majority, unfortunately.”
Tarantulas’ living conditions vary depending on species, but they often need to be kept at temperatures of between 22 and 30 degrees.
They normally feed on crickets and roaches.
The arachnids are believed to have been stolen between Saturday, August 31 and Friday, September 6.
Insp Mark Chamberlain, of the northwest neighbourhood policing team, confirmed the theft but said there was no threat to public safety.
Anyone with information is asked to call 101.